Advancing information communication and semiconductor technologies accelerate the spread and use of various portable terminals. Recently, portable terminals go beyond their respective unique functions and converge with other portable devices. A representative example of such convergence is the mobile communication terminal that may offer various additional functions, such as those provided by a television (TV) (e.g., digital multimedia broadcasting (DMB) or digital video broadcasting (DVB)) and a music player (e.g., an MPEG audio layer-3 (MP3) player), a digital camera, or Internet access, as well as its normal functions including voice calling or text messaging.
Wearable electronic devices have been recently developed, which are a sort of portable terminals and have shapes such as wristwatches, headsets, or glasses allowing the user to wear on a portion of his body. A wearable device may operate standalone or may interwork with another portable terminal (host device) to operate as a companion device to provide at least some (e.g., calling, messaging, or streaming) of the functions of the portable terminal to the user.